J Knee Surg 2017; 30(01): 78-87
DOI: 10.1055/s-0036-1581135
Original Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Influences of Tumor Necrosis Factor–α on Lysyl Oxidases and Matrix Metalloproteinases of Injured Anterior Cruciate Ligament and Medial Collateral Ligament Fibroblasts

Linyi Cai
1   State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China
,
Shu An
1   State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China
,
Jinfeng Liao
1   State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China
,
Wenbin Yang
1   State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China
,
Xuedong Zhou
1   State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China
,
KL Paul Sung
2   Laboratory of Biomechanics and Tissue Repair, Bioengineering College, Chongqing University, Chongqing, China
,
Jing Xie
1   State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China
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Publikationsverlauf

23. November 2015

21. Februar 2016

Publikationsdatum:
18. April 2016 (online)

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Abstract

The anterior cruciate ligament (ACL) fails to heal after injury, even after a primary surgical attempt. In contrast, the medial collateral ligament (MCL) can heal relatively well and restore the full joint function. The difference in intrinsic properties of these ligament cells can be due to their different responses to their local factors. TNF-α is considered to be an important chemical mediator in the wound healing of the ligaments. However, TNF-α–induced expression of lysyl oxidases (LOXs) and matrix metalloproteinases (MMPs) after injury is poorly understood. In this study, we use equi-biaxial stretch chamber to realize 12% stretch, which could mimic the injury to the ACL and MCL fibroblasts in vitro, and aim to determine the intrinsic differences between injured ACL and MCL by characterizing the differential expressions of LOXs and MMPs in response to TNF-α. The methods included Semiquantitative PCR, quantitative real-time PCR, Western blot, and zymography. We found that the mRNAs of LOXs had temporal increases in injured ACL and MCL. Moreover, the increases were higher in injured MCL than those in injured ACL (up to 1.77 ± 0.13-fold in LOX, 1.73 ± 0.21-fold in LOXL-1, 2.23 ± 0.27-fold in LOXL-2, 1.95 ± 0.11-fold in LOXL-3, 1.97 ± 0.28-fold in LOXL-4). On the other hand, the expressions of MMPs in injured ACL were much more prominent than those in injured MCL fibroblasts (up to 2.63 ± 0.20-fold in MMP-1, 3.73 ± 0.18-fold MMP-2, 1.58 ± 0.11-fold MMP-3, 4.23 ± 0.31-fold MMP-12). Similar results were observed at the protein level. The differential expression of LOXs and MMPs between the injured ACL and MCL fibroblasts in this study may help explain the healing abilities of the two different ligaments.

Supplementary Material